System and method of radio transmission and recetption



June 27, 1933. J. N JR 1,915,784

SYSTEM AND METHOD OF RADId TRANSMISSION AND RECEPTION Filed March 2, 1929 11 91 fly. 2

lNVENTO J0 N HAYS HAMM JR.

gj l dl&daiwd TORNEY Patented June 27,1933 1 4 1,915,784

UNITED STATES PATENT," oFFios JOHN HAYS HAMIEOND, JR., 01E" GLOUCESTER, MASSACHUSETTS SYSTEM AN D METHOD OF RADIO TRANSMISSION AND RECEPTION Application filed March 2, 1929. Serial No. 343,901.

The radiation of electro-magnetic waves case of a transmitter or in deriving space from various antennae will have a. polarized energy from either or both of said antennae effect in accordance with the direction of and supplying it to a receiver in the case of in the length of the antenna. Thus, a vertireceiving equipment. The amount of "15 cal antenna will transmit vertically polarized energy received from or transmitted on the 55 Waves, whereas, a horizontal antenna will two antennae being dependent upon the transmit horizontally polarized waves, or in amount of coupling of a rotatable coil to the other words, waves which may be best adapttwo antennae coils in each case. i 7 ed to be received by a similar antenna de- Ha-Ving now briefly described my inven- "1 pending upon distance and character of'in-' 13 1011 attention is invited to the accompanytervening territory. The effect of polarizaing drawing wherein, tion of the ether waves is quite pronounced Fig. 1 represents the horizontal and vertiand transmission from a vertically polarized cal antennae with their respective pick-up antenna, for instance, cannot be received efficoils and the adjustable pick-up coil for L ciently by horizontal antennae and vice versa. transferring power to or from the receiving But it has been observed that a wave polaror transmitting equipment respectively; ized in a given direction may be best re- F1g.2represents schematically the horizonceived on an antenna having a' certain dital and vertical antennae at the transmitting rection which need not necessarily, however, and receiving stations respectively; be the same as that of the transmitter and Fig. 3-represents the emission of a hori- 70 conversely that a given receiving antenna zontally polarized wave; will receive waves which have been polarized Fig. 4 represents the emission of a vertiin a certain direction better than otherwaves Cally polarized wave; which have not been polarized, although as Fig. 5-represents the emission of a Wave previously stated, the direction of the polarwhich is neither vertically or horizontallyization of the transmitter need not be the polarized; same as the direction'of the extent of the Rig; 6 is a schematic end view showing receiving antenna. I the exact relationship of the vertical and a ,4 It isan Ol)]e0t of the present invention to horizontal antennae; and

utilize the polarization characteristics of va- Fig.7 shows the direction of polarizatiou rious t a d th r vid a im roved of a wave being transmitted from the antenmethod of transmission and reception of na represented in Fig.6 when both antennae radiant energy. p are excited.

h It is a further object of this'invention to Having thus briefly described the figures '65 id a y t m of transmission and recepaccompanying this specification,- attention is $5 -tionof radiant energy which shall assist in inore particularly invited to Fig. l which the elimination of static. It is another 0bshows the vertical antenna 12 the circuit of ject of this invention to provide an improved which is grounded at 15 and contains the secsystem of transmission and reception which ondary or antenna coils l6 and17. l3 and shall be more free from the efiects' of inter- 14 represent thev diametrical portions of the 90 ference. 7 It is an additional object of this "horizontal antenna, the circuit ofwhich is ininvention to eliminate fading. These and eluded in'the antenna coils orsecondaries 18 other objects will become clearupon reading and 19. The rotatable coil 20 is connected M the following description of the-invention in 'to the output of a radio transmitter or to connection with the appended drawing. the input of a radio receiver by means of the 95 The apparatus involved in this invention connections or leads 21 and is adapted to be comprises, at each of the transmitting or rerotated so as to be inductively related to the ceiving stations using this system, a vertical coils in either or both of the two antennae. r and a horizontal antenna and means for ex- In the position shown the coil 20 is induc- J citing either or both of these'a'ntennae in :the 'tively related to the coils 18 and 19 and the entiretransmission in the case of a transmitter or the entire reception in the case of the receiver is through the horizontal antenna.

This is shown more clearly in Fig. 3 which represents a projection showing theground 31 with the horizontal antenna 26 and the horizontallypolarized wave represented at 32 being radiated in the direction 33.

If the coil 20 of Fig. 1 is rotated to the vertical position the entire energy transfer will be between itand the coils l6 and 17, and the radiation in the case of a transmitter will be as represented in Fig. 4. wherein the vertical antenna is shown as and the ra diation represented at- 37, in the direction 33 a and is polarized'in the vertical direction.

With the coil 20 at any intermediate position the entire'energy transfer between this coil and the two antennae will be proportioned in accordance with the angles between the axis of the pick-up coils of the two antennae L and the coil 20. "This is shown more clearly and 26 as they might be arranged relative to by the arrow 50 of Fig. l

in F 5 assuming the angle of the coil 20. .to be 45 with respect to both the vertical and horizontal antenna or in the direction shown by the arrow 50 or intermediate of the 7 direction of the vertical antenna 25 and the horizontal antenna 26. The radiation, in this instance, as diagrammatically represented at 51 in the direction 83, will be polarized as indicated. In thislatter instance, the. di-

rection of polarization is shown more clearlyv as being ate 5 with respect to the ground 31. I

The Fig. 6 is merely a view of the two an tennae 2 5 and 26 with respect tothe ground showing their actual angularity with respect to each other. a n

Fig. 2. shows the transmitting antennae 25 the receiving antennae 27 and 28. That is, the horizontal antenna would be parallel.

The operator will transmit inv the position in which his coil 20' may be and upon establishing communication with the receiver will,

the horizon, would be determined by the char acter of the intervening earth, etc. v

Now. if after communication has been established, interference is experienced at the receiver," the operator atthe receiving station may direct the transmitter to shift the angle of his coil 20 until the least interference is experienced, at the same time'rotating his owncoil 20 to continue the maximum pos sible reception. 01'. the receiver may rotate signal is then the complement of the interfer- .I am not to be limited by the a mum amount of energy in the" receiver circuit. In other words, the desired and undesired signals exactly neutralize each other with respect to the receiving antenna. The

ence and maybe easily read by'an experienced operator. 7 I

In a similarmanner the effects of static may be more or less eliminated, that is, the direction from which the static proceeds due 5. to the intervening terrain will result in causing the static impulses to be more or less polarized and by rotating the receiving pick-up coil 20 the effect of the static may be thus reduced. In this latter. instance, of coursefli? the transmitter operator is requested to tune his coil 20 to produce the best effect in the receiver. a

In a similar manner the eflects of fading may be greatly reduced if not entirely elim- 69 inated. Fading being caused by the effect of the fleavlside layer upon the reflected and operator of the transmitter is therefore re- I quested-to shift his transmitting coil 20 until 7 V I will now describe the operation ofmy 1nvention.

the least fading is experienced and the receivtransmitted signal the best.

Having thus described my invention it' is to be understood that a great many modifications and various embodiments may be devised from time to time and that, therefore,

specificv construction shown and described for the pur- .pose of illustration only, but by the scope of my inventionas set forth in the appended claims. 7

I claim: a

1. A method of radio transmission and reception which comprises transmitting the same signal with horizontally and vertically polarized ether waves, receiving said polarizedether waves and varying the efiect-ive' composite angle of polarization of reception thereof so as to produce substantially the best transmissionresults. 7

, 2. A method of radio transmission andreception which comprises'transmitting the same signal with horizontally and vertically polarized ether waves, separately receiving said differently polarized ether waves and adjusting the respective angles for inreception by receiving different amounts of each of the polarized waves, the proportion of receipt thereof being determined by the reception characteristics desired.

i. A method of receiving signals despite excessive interfering energy which comprises, shifting the angle of transmission with respect to the angle of reception so as to obtain a minimum amount of energy at the reception end whereby the signal is made the complement of the interfering energy, noting the complement of the interfering energy and obtaining the signal therefrom,

5. The method of receiving signals despite excessive interfering energy which comprises shifting the angle of reception with respect to the angle of transmission so as to obtain a minimum amount of energy at the reception end whereby the signal is madethe complement of the interfering energy, noting the reception of the interfering energy and translating the complement thereof to obtain the signal.

6. The steps in a method of radio transmission and reception which comprise transmitting waves representative of the same signals vertically and horizontally polarized in various proportions dependent upon the reception resultsat receiver, and intercepting both of the polarized waves and varying the amount of each thereof utilized for, in ef ect, varying the angle of polarized reception in accordance with desired 7 reception characteristics.

7. T he method of receiving signals despite excessive interference which comprises changing the. angle of polarized reception at a radio receiving station until the desired and undesired signals substantially V neutralize each other at the receiver and noting the signal from the complement of the interference.

8. A method of radio transmission and reception which comprises transmitting two sets of differently polarized ether waves, receiving said polarized ether waves, and shifting the polarization angle of transmission and the polarization angle of reception ofboth sets of waves in accordance with reception results at the receiver for obtaining good transmission results.

9. A signalling system adapted for use in localities subject to excessive interfering energy which comprises a vertical antenna system and a horizontal antenna system both thereof feeding'into an amplifier, means for shifting the angle of reception of signalenergy with respect to the polarization angle oftransmission thereof so as to obtain a minimum amount of energy at the receiver, comprising variable means for coupling said two antennae systems to said amplifier, said means being adapted to vary the proportion of energy fed from each of said two antennae to the amplifier, whereby the signal is made the complement of the interfering energy and means for translating the received energy for obtaining the. signal therefrom.

10. A signalling system adapted for use in localities subject to excessive interfering energy which comprises at the transmitter, a

vertical antenna system and a horizontal an tenna system, a sourceof signal energy, means for coupling said source to both said antennae systems comprising a variable coupling device adapted to transfer the signalling energy to said antennae systems in varying amounts depending upon adjustment thereof, means for receiving the transmitted energy from both systems comprising a vertical antenna and a horizontal antenna feeding into an amplifier system, means for shifting the angle of reception of signal energy with respect to the polarization angle of transmission thereof so as to obtain a desired amount of energy at the receiver, comprising variable means for coupling said antennae to said amplifier for varying the proportion of energy from each of said antennae to the amplifier whereby the signal is made the complement of-the interfering energy and means for translating the received energy for obtaining the signal therefrom.

JOHN HAYS HAMMOND, JR. 

